Protectant for irritated skin containing polyethyleneglycols, polyvinylether salt anhydride and polyvinylpyrrolidone

ABSTRACT

A smooth, greaseless skin ointment especially prepared for irritated skin, which protects, adheres and simultaneously is easily washable without causing skin damage. The ointment base is a blend of polyethylene glycols. It is combined with a bioadhesive which works synergistically to allow the blended ointment base to adhere to wet and moist areas, while not being so adhesive as to cause damage when removed in washing. Specifically a blend of polyethylene glycol polymers is prepared to provide good skin feel and drag, a polyvinyl ether anhydride salt bioadhesive is added and a polyvinylpyrrolidone is also used as a dispersant, and feces and urine toxicant binder. Optionally minor amounts of dimethicone can be added.

BACKGROUND OF THE INVENTION

This invention relates to a skin protectant, usually for use after skincleansing. It is a protectant that is especially designed for irritatedor compromised skin.

Ointments to be used on irritated skin in order to eliminate the painand irritating feeling are known. Most are petrolatum based and containa zinc oxide pigment in order to enhance wound healing.

A significant problem in use of these presently available skinprotectants, which are ointment based and contain zinc oxide, is thatthey in fact do not ideally protect compromised areas. Moreover, thepresence of zinc oxide, often compounds the problem of difficulty ofremoval during wound cleansing. Put another way, because the zinc oxideis somewhat difficult to remove, a nurse applicator is apt to over scrubin cleansing in order to remove zinc oxide. As a result, irritation isexacerbated, skin may be compromised or torn, and the ultimate healingprocess is delayed.

Problems such as those above described are very common in associationwith chronic diarrhea, enzymatic drainage, or incontinence. For use withthese three problems particularly, a skin protectant needs to one whichis greaseless, which provides a good moisture barrier, and one withexcellent adhesion to both moist and dry skin.

It is a primary objective invention to provide a skin protectant whichis especially designed for use with irritated skin normally associatedwith chronic diarrhea, enzymatic drainage or incontinence.

It is a further object of the present invention to provide a skinprotectant which adheres to both moist and dry skin, and yet which canbe easily removed during wound cleansing, without compromising ortearing the skin.

Another object of the present invention is to provide a non-greasyointment that does not contain zinc oxide.

A further objective of the present invention is to provide an ointmentespecially usable for compromised or torn tissue which has just theright amount of drag or feel, such that it can be applied to provide apleasant feeling and for good adherence and yet not being so tacky as totear skin.

A yet further object of the present invention is to provide a skinprotectant which is not petrolatum based, and which is easy to formulatesuitable for tubular dispensers.

The method and manner of accomplishing each of the above objectives aswell as others will become apparent from the detailed description of theinvention which follows.

SUMMARY OF THE INVENTION

A smooth, greaseless skin ointment which can be applied to provide skinprotective features on irritated and compromised skin whilesimultaneously being easy to remove. It comprises a blend ofpolyethylene glycol polymers designed especially to provide a viscositysuitable for pleasant skin feel without tearing the skin, and to providesuch a blend which has adhesiveness such that it will stay on moistskin, not run off, and yet be easy to remove. The composition alsocontains a polyvinyl ether and polyvinylpyrrolidone in criticalproportions to provide the adhesiveness characteristics to both moistand dry skin and yet also be easy to remove during cleansing.

DETAILED DESCRIPTION OF THE INVENTION

In its broadest sense, the invention comprises three major ingredients.The first major ingredient is a blend of polyethylene glycols with oneof those comprising from 50% to 80% by weight of the composition, andthe other from 15% to 35% by weight of the composition. The second majoringredient is a polyvinyl ether bioadhesive comprising from about 1% toabout 30% by weight of the composition. The third major ingredient ispolyvinylpyrrolidone at a level of from about 0.5% to about 30% byweight of composition. Optionally the composition may also contain asilicone, (dimethicone) at a weight ratio of from 0.1% to 5%. Each ofthe ingredients will be described in the order here presented.

Polyethylene glycols are known and are commercially available under thetrademark CARBOWAX® from Union Carbide. They are generally a family oflinear polymers formed by the addition reaction of ethylene oxide. Thegeneralized formula for polyethylene is:

    HO--(CH.sub.2 CH.sub.2 O).sub.n --H

wherein "n" is the average number of repeating oxyethylene groups.

The first polyethylene polymer of the blend of this invention is onewherein "n" represents 8.7. It has an average molecular weight of 400.It comprises from about 50% by weight to about 80% by weight of thepresent invention composition.

The second polyethylene glycol polymer is polyethylene glycol 3350. Ithas an average molecular weight of 3350. It comprises from 15% to 35% byweight of the composition. When these two polymeric glycols are blendedtogether it provides a homogenous texture and feel. It also provides thecorrect drag or resistance across skin to be perceived as pleasant, andat the same time, gives a base to the composition which does not simply"run off". These polymers all available commercially from Union Carbide.Detailed literature describing the polyethylene glycols, known asCARBOWAX® is available upon request from Union Carbide. The presentlybest known composition of the present invention is one which comprises69% of the polyethylene glycol average molecular weight 400 and 25% ofthe polyethylene glycol average molecular weight 3350. CARBOWAX® 3350has an average number of repeating oxyethylene units i.e. "n" of 75.7.

It is this blend of the two polyethylene glycols which forms theointment base and are collectively referred to as the first majoringredient.

The second major ingredient in the present invention is a bioadhesivewhich is not irritating and which will provide effective adhesivenessfor both moist and dry skin. The adhesive found to effectively coactwith the polyethylene based ointment blend is a vinyl ether polymer.Particularly preferred is a mixed sodium calcium salt of polymethylvinylether/maleic anhydride. It has the basic repeating structure: ##STR1##

It is readily dispersible to form colloidal dispersions in a wide rangeof media. It has high tack properties, especially suitable for adhesiveapplications. It has in the past been suggested for use as dentureadhesive and for ostomy products. It also has excellent cold watersolubility for easy removal upon washing. It is commercially availableunder the name GANTREZ MS-955 from GAF Corp. The amount used for thepresent invention is from 1% to about 30% by weight, preferably fromabout 2% to about 5% and most preferably 3%.

The third major ingredient of the composition of this invention ispolyvinylpyrrolidone, commonly referred to as PVP. It too is availablefrom GAF Corp., under the commercial product name PLASDONE K-90. It is ahighly pure, flake-like powder of the chemical structure: ##STR2## Ithas a weight average molecular weight of 1,200,000 and is used toprovide a colloidal protectant, and as well functions in the presentcomposition as a detoxicant for toxins of feces and urine. That is tosay it binds them so that they will not have access to a wound.

It is the combination and coaction of polyvinyl ether and thepolyvinylpyrrolidone in connection with the polyethylene blend ointmentbase which provides the excellent skin protectant nature of the presentinvention when blended in the amounts described. And it results in atype of skin protectant heretofore never achievable for nonpetrolatumbased protectant for irritated skin.

Optimally small amounts of a silicone can be added to enhance theelegance of the composition. Non-volatile polyalkylsiloxanes include,for example, polydimethylsiloxanes

(Dimethicone) with viscosities ranging from about 5-600,000 centistokes(cs) at 25° C. These siloxanes are available, for example, from theGeneral Electric Company as the VISCASIL series and from Dow Corning asthe Dow Corning 200 products. Preferably, the viscosity of thesesiloxanes selected have a viscosity of about 100 to about 100,000 cs,and most preferably, a viscosity of up to about 15,000 cs.

Suitable non-volatile polyalkylaryl siloxanes include, for example,polymethylphenyl siloxanes having viscosities of about 15 to 65 cs at25° C. These siloxanes are available, for example, from the GeneralElectric as SF 1075 methylphenyl fluid or from Dow Corning as 556Cosmetic Grade Fluid. Additionally, poly(dimethylsiloxane)(diphenylsiloxane) copolymers having a viscosity in the range of about10 to 100,000 cs at 25° C. are useful.

The following examples are offered to further illustrate but not limitthe process and product of the present invention.

                  EXAMPLES                                                        ______________________________________                                        (Formulation)                                                                 Component            % W/W    Amount                                          ______________________________________                                        Polyethylene Glycol 400, NF                                                                        69.0     483 Kg                                          Polyethylene Glycol 3350, NF                                                                       25.0     175 Kg                                          Polyvinyl Ether, Mixed Na/Ca, salt                                                                 3.0       21 Kg                                          Polyvinylpyrrolidone 2.0       14 Kg                                          Dimethicone          1.0       7 Kg                                           ______________________________________                                    

The above composition was examined, found to be nonirritating, nongreasy, easily wash removed without skin tearing, particular forincontinent patients and easily packaged in tube dispensers.

In particular, ten patients were treated in an open clinical study withthe foam and spray cleanser formulation of copending commonly assignedapplication Woller, Ser. No. 07/993,412, filed Dec. 21, 1992. Thereafterthey used the skin protectant formulation here described.

The clinical profiles of the ten patients used in this test varied fromincontinent of bowel with Foley catheter to experiencing erythema,edema, maceration, bleeding and/or ulceration in the perineal, and notresponding to treatments within continent wash and moisture barrierointment/zinc oxide ointment mixture, and patients with skin irritationsin the perineal area. Overall the open clinical involved twoinvestigators at separate hospitals treating a total of ten patients.Eight patients suffering from erythema, edema, maceration, bleedingand/or ulceration in the perineal area, were treated as above described.Overall the investigators obtained the following results.

Seven patients with erythema, edema, maceration, bleeding and/orulceration who had not responded to previous treatment protocols lastingtwo days to one month, healed within three to twelve days. One patientwith erythema, edema and maceration who had not responded to a previoustreatment protocol lasting five days, healed within five days andmaintained positive skin integrity for nine days. Two "at risk" patientsmaintained positive skin integrity for ten to eleven days.

The investigators concluded that the formulation foam cleanser and skinprotectant appear to be an effective system to assist the nursepractitioner in managing the skin of the incontinent patient. All showedsignificant improvement, patients described pain relief in abouttwenty-four hours, redness and irritation improved, as did skincondition.

It therefore can be seen that the invention accomplished at least all ofits stated objectives.

What is claimed is:
 1. A smooth greaseless skin ointment especiallyprepared for irritated skin which will protect and adhere whilesimultaneously being easily washable without causing skin damage,consisting essentially of:(a) from about 50% by weight to about 80% byweight of polyethylene glycol polymer of average molecular weight ofabout 400; (b) from about 15% by weight to about 35% by weight of linearpolymer of polyethylene glycol having an average molecular weight ofabout 3350; (c) from about 1% to about 30% by weight of a polyvinylether salt anhydride bioadhesive; and (d) from about 0.5% by weight toabout 30% by weight of polyvinylpyrrolidone.
 2. The composition of claim1 wherein the amount of linear polyethylene glycol of average molecularweight 400 is about 69% and the amount of linear polyethylene glycolpolymer 3350 is about 25%.
 3. A composition of claim 1 wherein thepolyvinyl ether sodium calcium mixed salt anhydride has the formula:##STR3## wherein "n" is the number of repeating units.
 4. A compositionof claim 3 wherein the amount of polyvinyl ether is from 2% to 5% byweight of the composition.
 5. A composition of claim 4 wherein theamount of polyvinyl ether is about 3% by weight of the composition.
 6. Acomposition of claim 1 wherein the amount of polyvinylpyrrolidone isfrom about 1% to about 10% by weight of the composition.
 7. Thecomposition of claim 6 wherein the amount of polyvinylpyrrolidone isabout 2% by weight of the composition.
 8. The composition of claim 1which contains from about 0.1% to 5% by weight of dimethicone.
 9. Thecomposition of claim 8 which contains from about 1% to 2% dimethicone.